Electric switch



A1li

` circuit'closer, the interrupting of theV circuit be.

Patented Mal?, 1.4,' 1939v UNITED -'STATES ELECTRIC SWITCH George R. Brown, Stratford, Conn., assignor'to General Electric Company, a corporation of New York Application January 2, 1936, Serial No. 57.104

8 Claims.

'I'he present invention relates to electric switches of the pull operated type and particuiarly to switches ofthis type having liquid con'- tact circuit closers for controlling the flow of current.

The object of my invention is to provide an improved -construction and arrangement in switches of this type, and for a consideration of what I believe to be novel and my invention attention is directed to the accompanying description and the claims appended thereto.

In the accompanying drawing, Fig. 1 is a front elevation of a switch embodyingmy invention with part of the casing removed in order more clearly to show the construction; Fig. 2 is a sectional end elevation of the switch; Fig. 3 is a fragmentary front elevation of the lower end of the switch showing the position of the pull member at the start of its return movement after moving the switch from one circuit controlling position to a. succeeding circuit controlling position; Fig. 4 is a view showing the construction and operation of the liquid contact circuit closer: and Fig. 5 is a sectional view taken on line 5-5 of Fig. 1.

Referring to the drawing,A I have illustrated my invention using a liquid contact circuit closer having a pair oi' cup-shaped metal terminals I which are separated by an insulating diaphragm 2 of a refractory material such as a ceramic material. The edges of the terminals are sealed by a bead 3 of glass which also seals the junctions between the diaphragm and the terminals. Within the space enclosed by the terminals is a suitable quantity of mercury 4 which forms the' conducting medium between the terminalsq In the manufacture of the circuit closer the space enclosed by the terminals is evacuated and filled with hydrogen at a pressure of one or more atmospheres which increass the current interrupting capacity of the circuit closer. As shown by the full lines in Fig. 4, the diaphragm -2 is provided with anopening 5 which is submerged ,in the mercury when the circuit'closer is in the current conducting position. When the circuit closer is in the currentl interrupting position.

shown in dotted lines in Fig. 4, the opening 5 isl above thefmercury, and, the circuit between the terminals is therefore broken by the insulatig diaphragm' 2. Due to the construction of the tweeiththe terminals-.takes placevin the mercury as the circuit closerv is turned so that the opening 5 is'lifted clear of the mercury. The above described construction is illustrative of liquid (Cl. 20D-156) contact circuit closers which are suitable foruse in a switch embodying my invention.

'I'he switch is enclosed within a. housing comprising complementary parts 6 and 1 of molded insulating material which are secured together 5 by clamping straps 8 and 9. The clamping strap 8 is provided with ears I0 for vmounting the switch.

The liquid contact circuit closer is supported for rotation about its axis by contact strips II 10 having projections I2 which ilt into depressions I3 formed in the terminals I of the circuit closer. The projections I2 on the contact strips and the depressions I3' in the terminals provide ball and socket connections for supporting the -switch for rotation about its axis and also for conducting electricity to the terminals. During the rotation of the circuit closer, the wiping action between the terminals and the contacts keeps the contact surfaces clean and tends toprevent increase of contact resistance. The contact strips Il aresecured to the part 6 of the housing-by the spun-over portions Il of inserts I5 molded in the housing. The line conductors are connected to the contact strips by means of terminal screws I6 threaded into the inserts. The circuit closer is rotated by means of a ring I1 of insulating material which is keyed to the terminal which faces the part 1 of the housing by means of a tongue I8 which iits into a depression in the 30 Y terminal. One of the contact strips I I overlaps the outer edge of the ring I1 and holds it on the terminal.

'I'he part -1 of the housing is provided with a boss I9 concentric-with the circuit closer winch 35 is provided with a slot 20 in which is secured one end of a spiral spring 2l. The free end of the spiral spring is xed to a pin 22 which projects over`the periphery of the ring' I1. A pull chain 23 is attached to the pin 22 by 'means of 40 a plate 24 which is pivotedon the pin 22 and which is provided with a tongue 25 having a slotted end which ilts between, adjacent balls .of the chain. A sheet 25a of insulating'materlal prevents contact of the spring 2| and the chain 4'5 23 with the adiacent contact II. The chain extends through an opening 26 in the lower end of and thereby center the Aswitch in the clampingr straps. t When the switch is in the position shown in Fig. 1, a pull on the vchain causes the pin 22 to 55 move between the ring il and the upper end of a barrier 30 into one of the notches 29 formed in the ring il and thereby to rotate the liquid contact circuit closer. The barrier 30 is formed on the part 6 of the housing and surrounds substantially half the periphery of the ring Il. Its function is to prevent movement of the pin 22 from the notch 29 while the pin is between the barrier 30 and the periphery of the ring Ill. If the chain is released while the pin 22 is in this position, the coil spring causes the ring l1 and the' circuit closer which is keyed thereto to be returned to the position shown in Fig. 1. This'prevents the circuit closer remaining in positions less than 180 apart. After the circuit closer has been turned through 180 the pin 22 moves from the notch 29 and passes through a passage 3l. formed between the lower end of the barrier 30 and a raised portion 32 on the housing 6. When the chain is released after the pin 22 has been moved below the lower end of the barrier 30, the coil spring 2i causes the pin to be moved to the outside of the barrier as shown in Fig. 3 and returned along the outside of the barrier to the position shown in Fig. 1. therefore rotate the liquid contact circuit closer through onlyla half revolution at each operation. At the end of one half revolution of the circuit closer, the opening 5 inthe-diaphragm 2 of the circuit closer is in the full line position shown in Fig. 4 and the circuit closer is in its current conducting position. At the end of the other half revolution of the circuit closer, the' opening 5 is in the current interrupting position shown in dotted lines in Fig. 4.

What I claim as new and desire to secure by Letters Patent in the United States is:

1. In combination. -a liquid v contact circuit closer supported for rotation, pull operated means biased to an initial position, a connection between the circuit closer and pull operated means effective when the pull operated means is in its initial position whereby the circuit closer is rotated away from and back to its initial position in accordance with movement of the pull operated means, and means for eifecting release of said connection upon a predeterminedrotationof the circuit closer whereby the circuit closer is independent of subsequent movement of the pull operated means toward and away from its initial position.

2. In combination, a rotatable member, pull operated means biased to an initial position and having a part adapted to engage and rotate said member, a barrier for holding said part -in `engagement with said member during a predetermined rotation of said member, and means including a passage to the outside of said barrier through which said part is moved for releasing the connection between said part and said member whereby said member is independent of subsequent movement of the pull operated means toward and away from the initial position.

returning said pull operated means to its initial 3. In a pull switch having parts movable to circuit controlling positions, operating mechanism for moving said Vparts to successive circuit controlling positions including a rotatable member, pull operated means having a part adapted to engage said memberand thereby positively rotate said member in either direction, means for position, means for disengaging said part from said member when the switch reaches a succeeding circuit controlling position whereby the pull operated means is returned to its initial position This switch operating mechanism will.

without affecting the rotatable member, and means for holding said part in engagement 'with said member whereby-upon release of the pull operated means prior to reaching the succeeding circuit controlling position said member is positively returned by the pull operated means to the preceding circuit controlling position.

4. In a p'ull switch having parts movable to circuit controlling positions, operating mechanism for moving said parts to successive circuit controlling positions including a rotatable member, a coil spring arranged on the axis of said member and having al pull member attached to the.

free end thereof, said pull member having a part adapted to engage said rotatable member and thereby rotate said member, means including a barrier for holding said part in engagement with the rotatable member until the rotatable member has moved said switch to a succeeding circuit controlling position whereby upon release ofthe pull member prior to reaching the succeeding circuit controlling position the rotatable member is returned by the pull member to the preceding circuit controlling position, means including said spring for moving said pull member from between said barrier and said rotatable member when the switch has been moved to said succeeding circuit controlling position and for returning said pull member to its initial position.

5. In a pull switch having parts movable to circuit controlling positions, operating mechanism for moving said parts to successive circuit controlling positions including a rotatable disk having symmetrically arranged stops on the periphery thereof, pull operated'neans having a part adapted to engage one of said stops and rotate said disk, means for returning the pull operated means to its initial position, means including a barrier for holding said part in engagement with said stop until said member has moved the switch to a succeeding circuit controlling position whereby uponrelease of the pull operated means prior to reaching the succeedingcircuit controlling position the disk is returned by the pull operated means to the preceding position, and means for releasing said part from said stop when the switch reaches a succeeding circuit controlling position whereby the pull operated means is re, turned toits initial position without aecting the switch. A

6. In a pull switch having parts movable to circuit controlling positions, operating mechanism for moving said parts to successive circuit controlling positions including a rotatable member having symmetrically spaced notches in the peripherythereof. pull operated means having a part adapted to engage one of said notches and positively rotate said member in either direction, means for returning the pull operated means to its initial position, means for holding said part in engagement with said notch until said member has moved the switch to av succeeding circuit controlling position whereby upon release of the pull operated means prior to reaching the succeeding circuit controllin'gposition said member is positively returned by the pull operated means to thepreceding position, and means for moving said part clear of said notch when Athe switch reaches a succeeding circuit controlling position whereby the pull operated means may be moved toward and away from its initial position without affecting the switch.

7. In a pull switch having parts movable to circuit controlling positions, operating mechanism for moving said parts to successive circuit conwww cuit controlling positions. operating mechanism trolling ponticns including a rotatable disk hav--l ing symmetrically spaced notches in the periphv ery thereof, pull operated means having a part adapted to engage one of said notches and vrotate said disk, means for returning the pull operated means to its initial position, means including a barrier for holdingsaid part in engagement with said notch until the disk has moved the switch to a succeeding circuit controlling position whereby upon releaseof the pull operated means prior to reaching the succeeding circuit controlling position the disk is returned by the pull operated means to the preceding position, and means for releasing said part from said notch when the switch reaches a succeeding circuit controlling position-whereby the pull operated means is re' turned to its initial position without ailecting the switch.

8. In a pull switch having parts movable to cirfor moving said parts to successive circuit controlling positions including a rotatable member, pull operated means having a part adapted to engage said member and thereby rotate said member, means including a barrier for holding said part in engagement with said member until said member has moved said switch to a succeeding circuit controlling position whereby upon 'release of the pull member prior to reaching the succeeding circuit controlling position the rotatable member is returned by the pull member to the' preceding 'circuit controlling position, means forr 

